Cement gun nozzle



March 21, 1933- CEMENT GUN NOZ ZLE Filed Dec. 30, 1929 1 .1. T. VAWTER1,902,202

JoH/v Vwrs/e HTTOIBNEY Patented Mar. 21, 1933 UNETEE STATES PATENTorrics JOHN T. VAWTER, OF LOS ANGELES, CALIFORNIA onmnn'r GUN vlvozzLnApplioationfiled December 30,1929. Serial No. 417,467.

a small percentage of the total amount of material conveyed, to a highpercentage of conveyed material depending largely upon the nature of thedeposited product desired. In cases where a dense compact concrete isrequired, it becomes necessary to apply the particles with a highvelocity in order to obtain a ramming action of the projected particlesand, consequently, a great amount of rebound takes place. But in caseswhere such 9 high density is not required but more nearly equals thedensity of average hand work, the rebound of particles introduces awaste of material and a loss of time. The control of rebound ofparticles in cement gun operation, 5 therefore, becomes of paramountimportance.

Accordingly, it becomes an object of this invention to provide a cementgun nozzle having means therein which operates as a'deterrent againstthe rebounding of particles.

Rebound, as it is used in this instance, may be defined as thereflecting of particles of material from a depositing surface; thereflected energy being due to the incident energy of each particle. Thisinvention, therefore, deals with the ballistic properties or incidentvelocity of the projected particles and is not primarily concerned withthe density of deposition only in so far as the characteristics of suchdeposits are efiected by the speed of the impacting particles. It,therefore; becomes another object of this invention to provide a nozzleof the character described characterized by having elements capable ofaltering the ballistic properties of the projected particles.

In considering the ballistics of the particles as related to rebound, itis clear that any change in the incident velocity of the particlesdirectly affects the percentage of rebound. Any decrease, therefore, inthe incident velocity of the particles'issuing from the nozzle orificeoperates to reduce the rebound of particles from a depositing surface.Accordingly, it becomes a further object of this invention to introduceinto a cement gun nozzle an obstructing element designed to retard theflow of the particles therethrough in a manner to decrease the velocityof the particles. I This invention, broadly speaking, contemplates thereduction of particle velocity by deflectmg the particles in transit andconsequently setting up a disturbance amongst; the particles whichappreciably-reduces their velocity. An additional portion of thevelocity' of the particles is absorbed by inefiective work performedagainst the sectional area'of the obstructing element transverse to thenormal particle movement. It is clear that by disturbing the normal flowof particles an agitation is set up amongst the par:- ticles thatinterrupts their flow and thereby converts a large amount of kineticenergy of the particles into heat that is rapidly dissipated by thevolume of air flowing therethrough. Manifestly,therefore, theparticlesafterpassing through such a zone of dis turbance must emergewith a greatly reduced velocity. A nozzle of the above character isespecially adapted for work when depositing upon a flat horizontalsurface where no high degree of densification is required.

In the embodiment of my invention shown and illustrated in the drawing,I have in-' corporateda deflecting arrangement in the" orifice of anozzle for use in combination with the ordinary cement gun equipment.

Other ob ects and advantages will become evident upon readingthedetailed descrippartly in see In all forms of my invention the principleinvolved deals with the impediment of the flow of the material particlesbefore leaving the nozzle orifice. For this purpose, I have illustrateda nozzle A, the walls of which flare outwardly and form an orifice 10 ofgreater diameter than the base of the nozzle. The nozzle A in turn isconnected in any suitable manner to a water ring B which is mounted uponthe end of a material conveying hose C. For retarding the materialparticles flowing outwardly through the nozzle A, I have provided anobstructing body D centrally positioned in the nozzle orifice 10. Asshown, the body D takes a somewhat stream line effect and operates todeflect the particles substantially as shown on lines 12.

By thus deflecting the particles from the normal course of travel, partof the kinetic energy of the particles is reduced to heat caused by thefriction of the particles amongst themselves and against the nozzlestructure and part is absorbed by the reaction against the transversesection of the obstructing element normal to the fiow of the particles.This results in appreciably reducing the velocity of the particles andis the primary object sought in this invention.

Means is provided for supporting the body D in the orifice of thenozzleA and preferably consists of supporting vanes 11 which support thebody D by extending the wall of the orifice. In respect to the mountingof the body D Within the orifice, it is understood that the meansshownisfor purposes of illustration only, and that any other means whichperforms the same function is acceptable for the purpose described. Thestruc-' ture thus provided is recognized as a means of dissipating aportion of the energy of the particles of a mixture and thereby reducingtheir velocity.

I am aware that various types of nozzles and various forms ofobstructing bodies may be utilized and the same results obtained, It is,therefore,'the intention of this invention to include all such forms ofnozzles and ob- I structing bodies that embody the principle of myinvention.

.1 claim as my invention:

A cement gun nozzle for projecting hydrated particles of materialcomprising, a nozzle having an expanded orifice, and an ovicular shapedmember centrally disposed in said nozzle, thedistance between the wallsof the nozzle and the ovicular men1ber increasing diametrically from thegreatest diameter of theovicular member to the orifice of said nozzle. I

In testimony whereof, I have hereunto set my hand at Los Angeles,California,-this 18 day of December, 1929.

JOHN T. VAWTER.

